The New Hampshire State House recently installed the en-Gauge fire-extinguisher monitoring system, which transmits devices’ operation and location data back to security centers. The system includes sensors, wireless backbone components and supervisory software that can be integrated into all major security and building-monitoring systems, said John McSheffrey, the company’s president.

Sensors monitor a fire extinguisher’s pressure gauge while it’s hanging on the wall. The device sends an electronic signal when the pressure level has dipped below an operable level — an important feature, considering that 25% of inspected fire extinguishers are below safe-operating pressure, McSheffrey said. Sensors also detect physical obstructions that affect its accessibility.

Each fire extinguisher can be hardwired, but most new installations are into buildings with wireless systems, McSheffrey said. Each extinguisher acts as wireless access points that can be part of a larger a network with the help of one repeater for every 10 units.

“Once the wireless is installed, you have the potential of adding more devices, like defibrillators,” he said.

Most importantly, buildings using such devices may be more code compliant, McSheffrey said. The proprietary software tracks the age, the in-service date and incident history, including usage and inspections, for each fire extinguisher.

“It lets users have easily accessible reports to demonstrate compliance with code enforcement bodies,” he said.

Wireless monitoring also ensures firefighters who address an incident at the state house know a fire extinguisher will be ready to be deployed, said William Degnan, the state fire marshal. In addition, he said the system provides an important security service; if someone removes a fire extinguisher to disrupt operations, or replaces it with an improvised explosive device, an alarm would be instantly triggered and wirelessly transmitted to building security, while mapping software on security personnel’s monitors help them deploy personnel.

“It’s like having wireless, 24-hour surveillance on this portion of fire protection 365 days a year,” Degnan said.

Fire extinguishers with scalable wireless packages cost from $300 to $500 per unit, McSheffrey said.